package com.example.myapplication2003;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.layout);

        // 通过id获取组件
        TextView textView = findViewById(R.id.text);

        // 修改显示内容
        textView.setText("=====");
    }
}